This invention relates in general to certain new and useful improvements in devices and methods used in the formation of dental restorations of the type used in the oral cavity of a human being, and, more particularly, to devices of this type which are easily manipulatable to perform a plurality of functions, as well as methods of using and making the same.
Dental restorations which are used in the oral cavity of a human being are usually constructed on a mold which becomes part of the dental restoration. These molds are typically formed of gypsum, a rather porous material which tends to absorb water. A metal frame is constructed around the gypsum mold and this metal frame is typically formed of a precious metal such as gold. Moreover, in the formation of the dental restoration, a restoration material is used to form the outer surface, and this restoration material is generally porcelain. The porcelain is applied to the metal framework around the gypsum mold and is thereafter baked on the framework.
It is fairly important that the porcelain restoration material be properly applied with the desired size and shape so as to resemble the appearance of a tooth normally appearing in the oral cavity. In addition, the dental restoration should be free from any small holes and like imperfections which would not only mar its appearance, but affect the quality and the life of the dental restoration. Other metals which may be used in addition to gold in the metal framework are platinum and palladium. It has been recognized that the metal oxides, particularly in the platinum and palladium, bond with the porcelain in order to form the dental restorations.
The porcelain restoration material, comprised mainly of feldspar, is a mineral substance containing aluminum oxide and silicon oxide, and may also contain potassium oxide, sodium oxide or calcium oxide. Feldspar is an effective restoration material since it is non-plastic and functions as an easily fusible binder. However, water is not missible with feldspar so that in any mixture of the feldspar and water, the water quickly settles out of or to the bottom of the feldspar-water composition. Nevertheless, in order to mold the feldspar, which is essentially the major component in the porcelain composition, it is necessary to have the water in the feldspar in order to render the same somewhat viscous to permit molding and shaping, as well as sizing of any composition produced therefrom. This is particularly true in the formation of dental restorations.
In the formation of the dental restorations in the past, the feldspar material has been mixed with the water and the producers of the dental restorations have attempted to work fairly quickly with a feldspar-water composition in order to permit the molding of the final dental restoration. If the water is allowed to settle from the feldspar-water composition, the porcelain can dry or "cure" fairly rapidly thereby preventing further working with the porcelain. This condition materially contributes to the difficulty in molding the porcelain into the desired shape and size. Moreover, this problem often results in a high loss rate of the work in progress. There have been several attempts to vibrate the dental restoration, or at least a portion thereof, during the formation of the restoration, in order to cause the feldspar to absorb the water and thereby permit easier molding thereof.
In the past, it was necessary for the technician to utilize several tools in order to form the dental restoration. One of these tools had a working end which was designed to pick up the porcelain from a source thereof and apply the same to a mold. Thereafter, another tool was utilized in order to pack the porcelain in a desired fashion. A third tool was necessary in order to shape the porcelain into the desired shape representative of a tooth in the oral cavity. Another tool was required in order to cut the porcelain and lift the same as may be desired. Several other tools were required in order to further shape the porcelain, compact, cut and perform other operations, in order to achieve the desired appearance. During the entire process, it was necessary to constantly create a vibratory action on the porcelain material, such that the porcelain material would hold the water, thereby enabling formation of the porcelain into the desired size and shape. In each case, the technician or other operator would use a tool or similar device to create the proper amount of vibratory action so that the water would temporarily be held by the porcelain during the vibratory action.
From the foregoing, it can be observed that one of the primary problems in forming the dental restorations encountered is the substantial time delays resulting from finding and selecting the proper tool for using the same in constructing the dental restoration. For example, if one of the tools which might be necessary at any step in the formation of the dental restoration is not immediately available, water would quick precipitate from the porcelain composition, thereby permitting the porcelain to set-up in a condition where it is not capable of being further molded. This resulted in a complete loss of the partially completed restoration. This condition is fairly prominent inasmuch as the technician often encounters substantial delay in selecting the proper tool and, in addition, creating the vibratory action which is necessary to cause the feldspar to hold the proper amount of water.